考虑剪胀角的节理化岩体隧道开挖进尺优化研究

合理进尺的选取是影响隧道开挖施工安全和效率的关键问题之一。以杨家坪隧道现场监测数据为根据，通过ABAQUS软件开展数值试算确定了最接近实际隧道围岩的剪胀角，建立了考虑剪胀角影响的Mohr-Coulomb模型的隧道开挖数值模型，并按1.5、2.0、2.5、3.0、3.5 m开挖进尺开展了计算，对开挖过程中隧道围岩的变形和力学响应规律进行了对比研究。结果显示，考虑剪胀角影响的数值模型计算结果的总体规律与实测结果一致性较好；有锚杆支护的情况下开挖进尺选择为3.0 m能较好地兼顾施工安全与效率，应注意控制距开挖面5.0 m范围内的拱顶变形。

Optimization of tunnel excavation footage in jointed rock mass considering dilatancy angle

Reasonable selection of excavation footage is one of the tunnel key points ,which affects the safety and efficiency of tunnel construction. Compared with the tested data of Yangjiaping tunnel, the most realistic rock dilatancy angle is acquired by numerical simulation with a software ABAQUS. A tunnel excavation numerical model considering dilatancy angle based on Mohr-Coulomb model is built, then the deformation and stress distribution of tunnel are analyzed under different excavation footages, 1.5, 2.0, 2.5, 3.0 and 3.5 m. Simulation results show that the numerical modeling results considered dilatancy angle is in good agreement with tested results; when the wall rock is supported with bolt support system, and choosing the excavation footage of 3.0 m, better safety and efficiency can be reached; but the deformation of tunnel roof within the scope of 5.0 meters from the excavation working face shall be paid more attention to.